'Meat glue' enzyme used in many restaurants

Most consumers wouldn’t know if they’re eating it

Before ABC News exposed the phenomenon of ‘pink slime’ earlier this year, few knew it existed. Now most are hearing about something called ‘meat glue’ for the first time, too.

It’s a little-known secret, used in the kitchens of many restaurants. Meat glue is the nickname for the white powder called transglutaminase enzyme.

It allows people to take small bits of meat – the size that would normally be used for stew - and bond them together in a way that makes the smaller pieces appear to be a solid steak.

"That looks like a normal piece of steak, doesn't it?," said Pennsylvania chef Doug Shirey. "Looks like a piece of filet mignon."

Shirey does not use meat glue at his restaurant, but agreed to demonstrate how it works. First he sprinkled the white powder over the meat, mixed and wrapped it up, then refrigerated it for 12 hours.

Rancher Nigel Tudor said meat glue is made by "taking the clotting agents out of pigs’ and cows’ blood" and using it "to clot together chunks of meat."

Not even an expert could tell the difference, even seeing the steak made with meat glue side by side with a real filet mignon.

"Look at that. It's amazing huh? Look at that," he said.

The federal government has said meat glue itself is "generally recognized as safe."

The packaging of meat sold at grocery stores must be labeled as "formed" or "reformed." But restaurants have no such labeling requirement, leaving consumers in the dark if their steak has been glued.

But Steve Steingart, of the Allegheny County Health Department in Pennsylvania said glued meat could also pose a health risk if smaller pieces of meat that have been handled, and possibly contaminated, end up in the center of a steak served rare.

He said glued steaks "would have to be cooked, because if you ordered this rare, there's a possibility that this steak, there could be growth on it."

"There's a deceptive quality we don't like about it," said restaurant owner Grainne Trainor. "And there's also a health and sanitation quality that we absolutely disagree with."

"Meat is something you buy at your neighborhood local butcher shop," Trainor said. "Glue is something you buy at Home Depot. Those two words just don't belong in the same sentence."